1. EARTHQUAKES

2. A movement or trembling of the ground that is
caused by a sudden release of energy when
rocks move along a fault line
EARTHQUAKES:

3. Rocks on both sides of a fault are pressed
together tightly locked by friction
When they finally, slip, vibrations occur
HOW THEY HAPPEN

4.  The location within the Earth along a fault at
which the first motion of an Earthquake
occurs
FOCUS:

5.  The point on the Earth’s surface above the
focus
EPICENTER:

6.  Waves that travel through the Earth
BODY WAVES:

7.  (Primary Wave)
 Motion is back and forth in the direction of
travel
 Fastest of the waves and can travel through
solids, liquids, and gases
 Compression wave
P-WAVE

8.  Secondary Wave
 Motion is side to side compared to direction
of travel
 Second fastest and can only travel through
solids
 Shear Waves
S-WAVE:

9. P WAVES VS. S WAVES

10. A seismic wave that travels along the surface
and has a stronger effect; converted P and S
wave, causes the most damage
SURFACE WAVES:

11.  Led to more in depth knowledge of the
Earth’s interior
 Various densities and phases are shown by
wave deflection
 S waves blocked by liquid outer core
 P waves change direction as they pass
through the cores
WAVES IN THE INTERIOR OF THE EARTH

12. WAVES IN THE INTERIOR OF THE EARTH:

13.  The longer the time difference between the
arrival of the P and S waves, the farther from
the epicenter
DETERMINING LOCATION

14. DIFFERENCE BETWEEN P AND S WAVES

15. DIFFERENCE BETWEEN P AND S WAVES

16.  Once you have the distance to the epicenter,
using readings from three stations, you can
determine the location by creating circle with
that distance as the radius. The point where
the three circles meet is the location of the
epicenter
DETERMINING THE LOCATION